This application brings together experienced researchers from Johns Hopkins and the YRG Centre for AIDS Research and Education (India) to plan a 'combined HIV prevention' approach among men who have sex with men (MSM). We propose a multi-level intervention targeting behavioral change at the community, network and individual levels implemented as a cluster-randomized trial of the effectiveness of Men's Wellness Centers on uptake of HIV voluntary counseling and testing (VCT). Indian MSM have a high burden of HIV and experience substance abuse and mental health problems that care. Yet Indian MSM remain hidden from public view as marriage is expected and anal intercourse has historically been a crime punishable by the Indian Penal Code (Section 377), only recently overturned. VCT services serve as an entry point for HIV treatment and medical care and can be scaled up to provide other prevention services. Our specific aims are: Aim 1: To characterize in-depth the nature of sexual identity, sexual practices, stigma and discrimination, health care access and health-seeking behaviors among MSM communities in Andhra Pradesh, Karnataka and Tamil Nadu (southern Indian states with high HIV burden) using qualitative research methods; Aim 2: To ascertain HIV/STI prevalence, prior VCT use, patterns of substance abuse, depressive symptoms, perceived and experienced stigma and health care needs among MSM across 12 sites (n=750 per site) in three southern Indian states through cross-sectional studies using RDS; Aim 3: To evaluate the effectiveness of MSM- friendly prevention centers on changes in risk behavior among MSM in southern India. Aims 1 and 2 are designed to identify factors that influence health care utilization and to identify discrete networks of individuals for the intervention. To achieve Aim 3, we propose a multi-level cluster-randomized trial among 4 pair-matched MSM community clusters (discrete networks of individuals that are identified in the baseline Aim 2 RDS). We will establish Men's Wellness Centers (DOST) in 4 intervention clusters and disseminate information about the centers through networks of MSM identified during the baseline RDS. These centers will provide culturally-appropriate prevention services including VCT, STI management, risk reduction and counseling for substance abuse and depressive symptoms. To assess community-level effectiveness, we will conduct an evaluation RDS among the 8 communities 18 months after implementation of the clinics to measure the primary outcome of proportion of participants tested for HIV in the prior 6 months in intervention vs. control clusters; secondary outcomes include (1) number of unprotected sex acts in prior six months; (2) number of non-primary partners in prior 6 months; (3) prevalence of HIV, HSV-2 and syphilis; (4) prevalence of substance abuse; and (5) prevalence of depressive symptoms. We will also perform analyses to assess success of the intervention at the network and individual levels. This study will provide evidence that improved, culturally-appropriate services for MSM will lead to more timely prevention, diagnosis and care of HIV infection in this group.